Window tinting has been widely used to control glare, radiated heat transmission, and illumination levels in the automotive and commercial markets, and to some extent in the residential market. The most common example of this can be seen in automotive windows. Residential use appears to be more limited because homeowners expect to be able to vary the amount of light coming in through their windows more so than they do in their cars. There is also the issue of privacy and security, which may not be as big of a concern in commercial buildings. Because of this desire to have flexibility in lighting levels, and privacy when required, homeowners still predominantly use combinations of curtains, drapes, blinds, shutters, and maybe tinted or even polarized film.
The typical application of window tinting consists of tinted or polarized film that is permanently bonded to the window, for example on car side windows or large commercial windows. While this technology offers some reduction in glare and relief from heat from the Sun, the fact that the film is permanently affixed to the window does not offer any flexibility in the amount of light transmitted or any option for privacy. There are, of course, high-end alternatives that consist of micro-crystals embedded in the fabric of the glass itself and are activated by applied voltage. However, most homeowners may find the cost of such systems to be prohibitive for residential applications.